2. OBJECTIVE
To give information about the poison and its
classification
To understand about the treatment in poisoning
To get information about the different antidotes for the
different poisoning
3. CONTENT
Toxicology
Branches of Toxicology
Types of poison
Catagories of poison
Medicolegal Classification of Poison
Genral Principal In The Treatment Of Poisoning
Antidote
Universal Antidote
Some examples of Antidotes
Common Modes of Action of Antidotes
Need For Antidotes
Classification of Antidotes
Activated charcoal
Demulsant
Chemical Antidote
Physiological and Pharmacological Antidote
Table of Antidote
4. TOXICOLOGY
DEFINATION
Toxicology deals with the study of adverse effects of chemical
substances on biological system due to their exposure. It includes the
study of mode of action of poison, symptoms of poison and treatments
associated with poisoning along with their detection in biological
system
Poison means Visha in Ayurveda
Visha Chikitsa or Agada Tantra include the treatment of diseases
caused by poisons and toxins, such as spoilt food, animal, reptile and
insect bites, poisonous minerals, metals and unsuitable food
combinations . It is equivalent to toxicology in modern medicine.
5. BRANCHES OF TOXICOLOGY
Branches of Toxicology
1. Analytical Toxicology
It deals with the evaluation of toxic substances present in
biological specimen as well as in raw form or crude form. And
their evaluation involves identification and quantification of
poisons using various analytical techniques.
2. Clinical Toxicology
It deals with diagnosis and treatment of human poising.
3. Forensic Toxicology
It deals with the analysis of toxic substances which involve
various methods to study the poisonous substances to aid the
legal investigation to know the cause of poisoning. It is a
medico-legal aspect of clinical poisoning.
6. 4. Veterinary Toxicology
It is the specialised branch of toxicology which deals
with the study, diagnosis and treatment of various
toxic compounds present in the animal kingdom.
5. Environmental Toxicology
It deals with the ill-effects of environmental toxicants
on human, animal, plants and on the environment
itself. Environmental toxicants are the compounds
which are released into environment from various
industries, hospitals, domestic wastage, etc, which
may be degradable or non-degradable.
BRANCHES TOXICOLOGY
7. CATAGORIES OF POISON
1. Corrosive Poisons
The poisons which cause inflammation on the site of contract are Corrosive Poisons,
comprising of both Strong acids (concentrated Sulphuric acid, Nitric acid and
Hydrochloric acid) and Alkalis.Strong bases: It includes both hydroxide and carbonate,
i.e., Sodium hydroxide, Potassium hydroxide and Ammonium hydroxide etc. Carbonate:
Sodium carbonate, Potassium carbonate etc.
2. Irritant Poisons
The poisons which cause irritation, pain and excessive vomiting are known as Irritant
Poisons, these poisons are further divided into:
(Inorganic Poisons)These poisons consist of both metallic (lead, arsenic,
mercury, antimony, bismuth, silver, copper, zinc etc.) and non-metallic (zinc chloride,
ferrus chloride, phosphate, sulphate, nitrate, nitrite etc.) compounds.
(Organic Poisons)It consists of poisons of both vegetable and animal
origin.Animal Poisons consist of Snakes venom, scorpion venom, cantharides
etc.Vegetable Poisonsare the huge class of poisons which contains various plants which
are toxic in nature (croton, castor, calotropis, nuxvomica, abrus, precatoreous, kaner
etc.).
(Mechanical Poisons)The poisons which cause irritation, perforation, obstruction in
the gastrointestinal tract, like powder glass, diamond dust, chopped hair etc.
8. 3. Neurotic Poisons
These poisons affect the different parts of central nervous system such
as Cerebral Poisons (alcohol, opium, barbiturates, and benzodiazepines) are
the examples of Ceberal poisons and are the Central Nervous System
depressing agents, Spinal Poison, the most common example and important
example of spinal poison in Strychnine, which is the active constituent that is
derived from the seed of strychnux nuxvomica, Peripheral Poisons, these are
the poisons which affects the peripheral nerves of the brain such as Curare.
4. Cardiac Poisons
The poisons which affects the cardiac system, for example Digitalis, tobacco
etc.
5. Asphyxiate Poisons
This category of poison which cause asphyxia to the cells or tissues.Asphyxia is
a condition of two sufficient supply of oxygen which results into shelter. The
best and common example of Asphyxiate is Carbon dioxide, Carbon Monoxide.
9. Types of Poisons
1. Solid Poisons
These poisons do not get absorbed easily into the blood.
These should be dissolved in liquid to get absorbed. For
example- Lead, Arsenic, Mercury etc.
2. Liquid Poisons
These poisons contain both organic and inorganic liquid.
Organic liquids are more volatile than inorganic liquids.
3. Gaseous Poisons
These poisons are absorbed by inhalation such as carbon
dioxide, carbon monoxide.
10. Medico-Legal Classification of
Poisons
1. Based on Intention
(A) Homicidal Poisons
The poisons which are used to kill the other person are known as homicidal poisons such as aconite,
abrus precatorius, arsenic, etc.
(B) Suicidal Poisons
Those poisons which are used for self-killing such as opium, barbiturate, agricultural poisons etc.
(C) Accidental Poisons
These poisons which cause toxicity by accidents or are used in mistaken of others: Snakes bite, CO are
the examples of accidental poisons while sometimes child takes dhatura’s seeds in mistaken of capsicum
seeds as these resemble to capsicum seeds.
(D) Abortifacient Agents/ Poisons
The poisons which are used to procure abortion are known as abortifacient poisons for example Quinine
(alkaloid), Calotropis, croton, oleander, marking nut etc.
(E) Stupefying Agents/ Poisons
Those are the substances which are used to stupefy the human being. For example Dhatura, Chloral
hydrate etc., these are used to rob the stranger or for the commitment of other crimes.
11. 2. Bases of Method
(A) Volatile and Gaseous Poisons
Isolated by distillation are categorized into this group. And the volatile substances can be separated from
gaseous.
Volatile substances are methanol, ethanol, benzene, toluene, acetone, chloroform, chloral hydrate etc.
Gaseous Poisons are ethane, butane etc.
(B) Organic Non-Volatile Poisons
Isolated by solvent extraction methods include in this group. This is a very wide category of poison which
contains rugs such as opiates and synthetic narcotics, sedatives, hypnotics, stimulants, etc.
These are the alkaloids that derive from opium, and operates are regulated under NDPS i.e., Narcotic
Drugs and Psychotropic substances.
The muscle relaxant and are used to relieve anxiety. These are also CNS depressants.
LSD, amphetamine, cocaine etc. are the best examples of stimulants.
(C) Metallic Poisons
The substances which are isolated by dry ash method or by wet digestion method constituting this group.
The common poisons of this group are arsenic, lead, mercury, antimony, bismuth etc.
(D) Anion
Anion is Isolated by dialysis. Most commonly encountered anions in poisoning cases are bromide,
cyanide, fluoride, hypochlorite, nitrate, nitrite, phosphate, sulphite, sulphate etc.
12. GENERAL PRINCIPLES IN THE TREATMENT OF POISONING
Intentional and accidental poisonings are major medical problems. Every natural or
synthetic chemical can cause injury if the dose is high enough.
The single most important treatment of poisoned patients is supportive care.
This is so important. You must treat the patient and not the poison. Provide airway
support and ventilation and support blood pressure if needed. Toxicology screens of
blood or urine take time and rarely change your therapy. If you know the poison, great;
if not, treat the patient.
To reduce absorption in an alert, relatively asymptomatic patient, use activated
charcoal.
Three procedures are widely used to reduce the absorption of poisons from the GI
tract: inducing emesis, gastric lavage, and activated charcoal. To be effective, emesis
must be induced within 1 hour of ingestion, and it works best if induced within 5
minutes of ingestion. Gastric lavage needs to be carried out within 1 hour of ingestion.
Emesis induced with ipecac and gastric lavage only empties the stomach. Any poison
that has moved into the small intestine is not removed. Activated charcoal remains in
the GI tract, absorbing poison throughout.
13. To enhance elimination, a number of techniques can
be used. Multiple doses of charcoal reduce the half-life
and increase clearance. Increasing the pH of the urine
enhances elimination of weak acids. Hemodialysis and
hemoperfusion can be used to help remove specific
agents from the blood
14. ANTIDOTE
An antidote is a drug, chelating substance, or a
chemical that counteracts (neutralizes) the effects of
another drug or a poison.
There are dozens of different antidotes; however, some
may only counteract one particular drug, whereas
others (such as charcoal) may help reduce the toxicity
of numerous drugs. Most antidotes are not 100%
effective, and fatalities may still occur even when an
antidote has been given. Some examples of antidotes
include:
15. Constituents of universalantodote
S. No.
Constituents
Quantity
Purpose
constituents qualitity purpose
1 Powered charcoal 2 part Abbsorb alkaloid
2 Magnesium oxide 1 part Neutralize acid
3 Tannic acid 1 part Precipitaters
alkaloids,certain
glucosides and
many metals
16. UNIVERSAL ANTIDOTE
Activated charcoal
If the nature of administrated poison is not known and it is
suspected that two or more poisons have been taken. Inthose
cases the universal antidotes are administered. They are
simply the mixture of easily available substances.Usually it is
a combination of Physical and Chemical Antidotes. They are
not very effective, even if they after give soon after the
administration of the poison. S. No. Constituents Quantity
Purpose 1. Powdered charcoal 2 parts Adsorbs alkaloids 2.
Magnesium oxide 1 part Neutralize acids 3. Tannic acid 1 part
Precipitates alkaloids,certain glucosides and many metals
Dose: The mixture can be taken in a tablespoonful stirred up
in a glass of water and may be repeated once or twice.
17. SOME EXAMPLES OF ANTIDOTE
Acetylcysteine for acetaminophen poisoning
Activated charcoal for most poisons
Atropine for organophosphates and carbamates
Digoxin immune fab for digoxin toxicity
Dimercaprol for arsenic, gold, or inorganic mercury poisoning
Flumazenil for benzodiazepine overdose
Methylene blue for drug-induced methemoglobinemia
Naloxone for opioid overdose
Pralidoxime for poisoning by anti-cholinesterase nerve agents.
18. 3. Common Modes of Action of
Antidotes
3.Common Modes of Action of Antidotes
Here are some of the common modes of action in
which the antidote functions: 1) By the formationof inert
complex. e.g; chelating agents for heavy metals, dicobalt
edentate for cyanide. 2) Accelerated detoxification, e.g;
thiosulphate is used as an antidote for cyanide. 3) Reduced
toxic conversion, e.guse of ethanol for methanol poisoning.
4) Blockage of receptor site, e.g naloxone for opiates; atropine
for organophosphates at muscarinic receptor sites 5) Bypass
toxic effect, e.g 100% oxygen in cyanide poisoning
19. 4. Need For Antidotes
The poison is required to be expelled out of the body as
soon as possible. Therefore there is a need to administer
antidote because emesis or gastric lavage or other
procedures may not completely help remove the poison
from the body. Or if the poison is administrated other
than the route of ingestion, it need to be removed
immediately. In other condition the poison may already
be absorbed, so it become more important to make use
of the antidotes to discharge the poison out of the body.
20. 5.Classification of Antidotes
Antidotes are classified on the basis of their mode of
action and are grouped into following four categories:
1) Mechanical or Physical Antidote
2) Chemical Antidote
3) Physiological or Pharmacological Antidote 4)
Universal Antidote
21. 5.1 Mechanical or Physical
Antidotes
These are the substances that neutralize the poison
and they also help stop the absorption of poison in the
body. They are further sub-grouped as following based
on their functions; a) Activated charcoal b)
Demulcents c) Bulky food
22. 5.1.1Activated charcoal Activated charcoal is fine black,
odourless powder. It is manufactured by the
destructive distillation of various organic materials
mainly wood pulp and then treated at high
temperatures with a variety of activating agents such
as steam, carbon dioxide etc. Activating Agents help
increase the absorptive capacity. It has a property of
small particle size and the surface area is very large.
Slurry is prepared by mixing it with water and can be
used for treatment.Activated Charcoal acts by delaying
the absorption of poison from the stomach. Activated
charcoal is particularlybeneficial in adsorbing the al
23. 9
Akaloidal poisons, such as strychnine and to a lesser degree,
mineral poisons. In multiple doses it significantly increases
the total body clearance of Opium, Cyanide and
Phenobarbital. Phenol, Salicylates, Kerosene and Paracetamol
are moderately absorbed. The limitation of activated charcoal
is that it is not very useful in dealing with the cases of
corrosives, heavy metals, hydrocarbons and alcoholpoisoning.
Dose It is given in a dose of 30-60grams in children and 60-
100grams in adults in five times the quantity of water. The
correct dose of activated charcoal is about 5 to 10 times the
amount of drug ingested.
24. 10
5.1.2 Demulcents Demulcents are capable of forming a
protective coating on the gastric mucous membrane thus
preventing the damage caused by the poisons. Demulcents
include fatty products like egg, milk,albumin,oil etc. But fat
and oils should not be used for oil-soluble poisons such as
kerosene, phosphorus, organophosphorous compounds,
DDT, phenol, turpentine, aniline, acetone etc. They act in
the same manner both in corrosive and irritant poisoning.
5.1.3 Bulky food The mechanism of action of bulky food on
poison is similar to mechanical antidotes. They allow
imprisoningof the particles on its surface.Eg.banana acts as
a mechanical antidotes to glass by imprisoning its particles
and thus preventing its action.
25. 5.2 Chemical Antidotes
The chemical antidotes inhibits the action of poison by forming harmless or
insoluble compounds or by oxidizing poison when brought into contact with
them. For eg. Potassium permanganate has oxidizing properties. It is used as
solution in a ratio of 1:5000 for opium and its derivatives, strychnine,
phosphorous ,hydrocyanic acid, cyanides, barbituric acid and its derivatives
atropine and other alkalis.It loses its pink color in stomach when it reacts with
the poison.Some other examples are as follows: v Tannin(strong tea) produces
insoluble compounds with most alkaloids,glucosides and metals. v Common
salt decomposes silver nitrate by direct chemical action, forming the insoluble
silver chloride. v A solution of tincture iodine or lugol’s iodine (15 drops) to half
a glass of warm water precipitates most alkaloids, lead,mercury,silver,quinine
and strychnine. v Alkalis neutralize acids by direct chemical action. v Acid
neutralizes alkalis by direct chemical action. Only those substances that are
harmless by themselves should be given e.g;vinegar,lemon juice, canned fruit
juice. Neutralization of acids with alkali and vice versa should be avoided
because exothermic reaction of neutralization can cause additional injury
26. 5.3 Physiological and
Pharmacological Antidotes
These agents acts on the principle of antagonism.
Most of the known antidotes are only partial
antagonist in their action. They act on tissues of the
body and produce symptoms exactly opposite to those
caused by the poison. They are not dangerous but their
use is limited. The two real physiological antidotes are
atropine and physostigmine. They act on nerve
endings and produce opposite effect on heart rate.
Other examples are cyanide and amyl nitirate,
barbiturates and picrotoxin or amphetamine.
27. 6. Chelating Agents as Antidotes
Certain Chelating agents are extensively used as an antidote for the heavy metal poisoning. They function by
forming a firm non-ionized cyclic complex with captions. These completxes are stable, soluble, on-toxic and
complexes with calcium and certain other heavy metals. Due to this they have high renal excretion capacity.
The strongest of all the available chelating agents are EDTA, B.A.L and Penicillamine. 6.1 EDTA (
Ethylenediaminetetraacetaic acid) It is a chelating agent and used in mercury, cobalt, cadmium, iron and
nickel poisoning. The usual adult dose is 1gram of EDTA twice a day for period of five days. It is usually
administeredby slow intravenous infusion in isotonic glucose saline. The complex of chelates is formed with
lead which are water-soluble, non-toxic, non- ionised, non- Antidotes .Antidotes are the dose of any
substance, which counteract or neutralize the effects of poisons without causing appreciable harm to the
body. v Antidotes have their own significance in clinical toxicology. There are many poison information
centers, which help in recommending the antidotes for the specific type of poisons. v Antidotes are also
classified on the basis of their mode of actioninto mechanical and physical antidotes,chemical
antidotes,physiological and pharmalogical antidotes, and universal antidotes. v There are some chelating
agents, which forms a non-ionized cyclic complex with cations. v The complex of chelates is formed with
lead which are water-soluble, non-toxic, non- ionised, non- metabolised and excreted intact in the urine. v
The strongest of all the available chelating agents are EDTA, B.A.L and Penicillamine.
28. Dose:
Dose: The mixture can be taken in a tablespoonful
stirred up in a glass of water and may be repeated once
or twice.